A pilot-scale, two-stage (carbon oxidation stage one, ammonia oxidation stage two) fixed film biological aerated filter (BAF) process was operated on-site at a domestic wastewater treatment plant. Over the study period, hydraulic loadings to the system were varied, generating a range of organic and ammonia loading conditions. Nitrification was monitored along the length of the filters by measuring chemical nitrogen species and activity levels of ammonia oxidizing bacteria (AOB). During the first phase of the study, nitrification performance was characterized during the wintertime and compared with oligonucleotide probing results using an ammonia-oxidizer specific probe. Overall nitrification efficiency for wintertime conditions (average temperature 12.4 ± 0.1°C) was greater than 90 percent when ammonia-N loadings to the second stage were 0.6 kg/m3-day or less. Nitrification efficiency started to deteriorate at loadings beyond this point. Biofilm and liquid samples were collected along the distance of the two columns at high and low ammonia loadings. The degree of activity observed by ammonia oxidizing bacteria in the biofilm corresponded with the disappearance of ammonia and the generation of nitrate as water passed through the columns. During the second phase of the study, the probing methods were investigated and results of two approaches of analysis were compared to chemical nitrogen profiles. It was found that probe signals normalized to mass of total bacterial nucleic acid corresponded better with chemical profiles than using a novel method of standardizing against known nucleic acid mass standards. During both phases of the study, zones of ammonia oxidizing activity progressed along the length of the columns as organic and ammonia loadings to the system increased. The oligonucleotide probe data suggest that this shift in the location of the nitrifier population is due to higher BOD loads to the second stage, which supported higher levels of heterotrophic growth in the second stage of the system. It was concluded that the strongest influence on nitrification performance in this type of BAF system is likely to be competition between heterotrophs and autotrophs. / Master of Science

The key challenge in mobile ad-hoc network (MANET) is the design of routing protocol which adapting their behavior to frequency with rapid changes in the network. As we have known, there are two main kinds of routing protocols in MANET: proactive and reactive routing protocol; and in addition, authors [1] proposed to use location information provided by positioning devices such as global positioning systems (GPS) to assist routing. We wonder whether the assumption of all devices in the communication area have the GPS ability is reasonable; furthermore, a GPS-enabled device has its own limitation on working areas; for example, the GPS ability cannot work in the indoor environments. In this paper, (1) we tried to addition the mechanism of probing routing redirection/discovery at routing protocol in AODV. Using overheard node avoid route breaking and select route batter than origin.(2)we tried to use the property of GPS to solve the routing problems in MANET, which like broadcast storm in the route discovery, device power saving and optimal one-hop destination, channel reuse rate, and optimal routing path. According to 802.11 specification, the best way to reach the goal of device power saving is putting device into the sleep mode. In this routing protocol, we let most mobile devices stay in the sleep mode until it sends or receives data or acts as an intermediate node to forward data. Last, we use simulations and implementation to validate the effectiveness of our design.

The domain of distributed simulation is growing rapidly. This growth leads to larger and more complex supporting network architectures with high requirements on availability and reliability. For this purpose, efficient fault-monitoring is required. This work is an attempt to evaluate the viability of an Active probing approach in a distributed simulation system in a wide area network setting. In addition, some effort was directed towards building the probing-software with future extensions in mind. The Active probing approach was implemented and tested against certain performance requirements in a simulated environment. It was concluded that the approach is viable for detecting the health of the network components. However, additional research is required to draw a conclusion about the viability in more complicated scenarios that depend on more than the responsiveness of the nodes. The extensibility of the implemented software was evaluated with the QMOOD-metric and not deemed particularly extensible.

Cracked teeth may be difficult to diagnose. Craze lines rarely become symptomatic or require treatment. Cracks in the enamel and dentin alone may or may not become symptomatic and require restorative treatment. However, cracks extending into the enamel, dentin, and pulp chamber provide an avenue for bacteria to establish infection and this commonly results in symptoms and the need for endodontic and restorative treatment. The published endodontic literature has limited information regarding the prevalence or predictive factors for cracks extending into the pulp chamber of teeth. The purpose of this study was to determine the prevalence and classification of intrapulpal cracks in maxillary premolars and to identify factors that may aid in diagnosing the existence and extent of a crack. The cracks were classified according to the Intrapulpal Crack Classification System proposed by Detar in 2014. All maxillary premolar teeth treatment planned for non-surgical root canal therapy (NSRCT) or retreatment (RETX) at Virginia Commonwealth University (VCU) Graduate Endodontic Practice from January 2014 through February 2015 were included in the study after obtaining patient consent. Teeth were examined visually, stained, and examined microscopically for the presence of an intrapulpal crack. Demographic information, subjective data associated with the chief complaint, objective results of diagnostic testing (percussion, palpation, bite stick test, transillumination, probing depths), existing restorations, pulpal diagnosis, and periapical diagnosis were analyzed using chi-square and multiple logistic regression (P

Visual analysis of an object's size can be used to determine the lifting forces we program to lift the object so that the resulting movements achieve the goals of the lift. These forces are scaled or specified prior to the object moving, that is, before sensory feedback information about the object's weight is available. Sensorimotor memories are relied on to provide relevant information about an object's density and weight if the object was previously manipulated. It is well established that young adults accurately scale their forces based on visual size cues. The purpose of this study was to determine if old adults scale their forces to the size of the object or if they rely on sensorimotor memory of the previous object's weight. There are reports of impaired visuomotor programing for grasp and lift in old adults. In the present study old and young subjects were required to lift four different sized bottles of constant density from a force plate and then place the object on a shelf. Two experiments were performed. Experiment one featured blocks of lifts for three bottles in the following order: large, small and medium. Experiment two took place fifteen minutes after experiment one and featured a bottle slightly larger than the medium bottle used at the end of the experiment one. The second experiment addressed whether imperceptible changes in size cause changes in predictive force scaling. Peak load force rate in the first force pulse (prior to lift-off) was measured for each lift of the objects with the focus being on the initial and last lift of each bottle. Both experiments presented a significant effect for bottle size on lift force rates. This result was found regardless of age. It provides additional support that young adults accurately scale their lift force rate based on the visual size cues of the object. Old adults also demonstrated scaling of their lift force rates based on bottle size which failed to support the hypothesis that old adults would merely reproduce their lift force rates from the previous lift with a different object. While both young and old scale lift forces to object size, the old demonstrated a trend for utilizing high lift force rates throughout the experiment as well as greater differences in lift force rate between the initial lift with an object and the final lift with the same object. Most subjects utilized a target strategy in which they produced a single peak lift force rate pulse. This is indicative of a neural representation of the weight of the object being utilized to program the lift force rate. The remaining subjects exhibited a probing strategy that features several step-wise increases in lift force rate until the object is lifted off. This represents a more cautious approach to lifting novel objects. Our results indicate that old adults, much like young adults, are able to scale their forces based on visual size cues.

¡@¡@In this Thesis, we proposed a new SVC Layer Scheduling Algorithm (CSDB, Chunk Scheduling with Delay-trend and Bandwidth-monitoring) in SVC-P2P Video Streaming by using RTT Probing and Bandwidth Monitoring mechanisms to measure RTT/2 and historic bandwidth between peers simultaneously. When transmission delay (TD) dominates in the end-to-end delay and when instantaneous bandwidth increases, peer will quickly increase the downloading layers of video segment (VS). On the other hand, when instantaneous bandwidth decreases, peer will decrease the number of layer chunks (LCs) not in time according to RTT/2 and historic bandwidth. When queuing delay (QD) and propagation delay (PD) dominate in the end-to-end delay, peer will assume RTT/2 is accurate because every LC is in time. In this case, peer will quickly increase the downloading layers; otherwise, peer assumes there is a big difference between RTT/2 and one-way delay (OWD) such that it will decrease the downloading layers to half. When peer cannot grab VS in time according to measured RTT/2 but every LC grabbed is in time, peer will assume there is a big difference between measured RTT/2 and OWD. In this case, peer will keep no change in downloading layers; otherwise, peer will assume measured RTT/2 is close to OWD, and it will decrease the downloading layers to half. ¡@¡@In order to demonstrate the advantages of CSDB, we designed a simulator written in C++. In the simulation, we consider two scenarios: 1) When TD dominates. 2) When QD and PD dominate. Simulation results show that peer can achieve high quality SVC video by balancing the number of received layers and the number of LCs not it time.

No description available.

There has been an increase in demand for the wafer-level test techniques that evaluates the functionality and performance of the wafer chips before packaging them, since the trend of integrated circuits are getting more sophisticated and smaller in size. Throughout the wafer-level test, the semiconductor manufacturers are able to avoid the unnecessary packing cost and to provide early feedback on the overall status of the chip fabrication process. A probe card is a module of wafer-level tester, and can detect the defects of the chip by evaluating the electric characteristics of the integrated circuits(IC's). A probe card analyzer is popularly utilized to detect such a potential probe card failure which leads to increase in the unnecessary manufacture expense in the packing process. In this paper, a new probe card analysis strategy has been proposed. The main idea in conducting probe card analysis is to operate the vision-based inspection on-the- y while the camera is continuously moving. In doing so, the position measurement from the encoder is rstly synchronized with the image data that is captured by a controlled trigger signal under the real-time setting. Because capturing images from a moving camera creates blurring in the image, a simple deblurring technique has been employed to restore the original still images from blurred ones. The main ideas are demonstrated using an experimental test bed and a commercial probe card. The experimental test bed has been designed that comprises a micro machine vision system and a real-time controller, the con guration of the low cost experimental test bed is proposed. Compared to the existing stop-and-go approach, the proposed technique can substantially enhance the inspection speed without additional cost for major hardware change.

Proactive and nondisruptive channel probing is investigated for the measurement of channel power, amplifier channel gain, and optical signal-to-noise ratio (OSNR) without disrupting established wavelength-division multiplexed channels. Using a nondisruptive probe signal over a three-span link, wavelength switching-induced power excursions are predicted to be within +/- 0.2 dB, and OSNR as high as 20 dB is accurately measured with a maximum of 0.5 dB error.

Infrastructure-as-a-Service cloud platforms are incredibly complex: they rent hundreds of different types of servers across multiple geographical regions under a wide range of contract types that offer varying tradeoffs between risk and cost. Unfortunately, the internal dynamics of cloud platforms are opaque in several dimensions. For example, while the risk of servers not being available when requested is critical in optimizing these risk-cost tradeoffs, it is not typically made visible to users. Thus, inspired by prior work on Internet bandwidth probing, we propose actively probing cloud platforms to explicitly learn such information, where each "probe'' is a request for a particular type of server. We model the relationships between different contracts types to develop a market-based probing policy, which leverages the insight that real-time prices in cloud spot markets loosely correlate with the supply (and availability) of fixed-price on-demand servers. That is, the higher the spot price for a server, the more likely the corresponding fixed-price on-demand server is not available. We incorporate market-based probing into SpotLight, an information service that enables cloud applications to query this and other data, and use it to monitor the availability of more than 4500 distinct server types across 9 geographical regions in Amazon's Elastic Compute Cloud over a 3 month period. We analyze this data to reveal interesting observations about the platform's internal dynamics. We then show how SpotLight enables two recently proposed derivative cloud services to select a better mix of servers to host applications, which improves their availability from 70-90% to near 100% in practice.